Since the advent of electronic devices there has been extensive research and development in the creation and advancement of electronic musical instruments. Some electronic musical instruments are specifically arranged to emulate their acoustic equivalents, while others are designed to enable musicians to create new and exciting sounds.
Most musical instruments provide various means for controlling characteristics of pitch and volume. Many acoustic musical instruments allow musicians to vary these properties as a note is played, and to influence the timbre of sounds, which may be affected by characteristics of the way in which the instrument is played. For example, characteristics can be imparted on the sounds made by an acoustic musical instrument by a musician playing the instrument adding effects such as vibrato. This control of the sound made by an instrument provides musicians with their own musical personality. There has always been a desire to impart such personality to the sounds produced by electronic instruments.
Electronic musical instruments generally produce signals that are sent to a processor arranged to create one or more sounds responsive to inputs from a user on an interface. It is particularly easy to process electronically originated sounds in order to vary many different characteristics of the sounds. However, a problem for engineers producing electronic musical instruments is the development of a user interface that gives the user control over such characteristics of the sound at their fingertips, as is possible with most acoustic musical instruments. Hence, the development of the interface for electronic musical instruments is of particular importance for providing musicians with increased and improved natural control of the instrument.
A further consideration concerns the fact that acoustic instruments often provide both tactile and visual feedback to the user, such as the sounding of a note in combination with the bending of a string or the depression of a key. Providing a similar quality of multi-sensory feedback to musicians using electronic instruments can be difficult.